<!DOCTYPE HTML>
<html> 
<head>
<script language="javascript">
function draw() {  
    var ctx = document.getElementById('myCanvas').getContext('2d');
    var radgrad = ctx.createRadialGradient(55,55,20,100,100,90);
    radgrad.addColorStop(0,'#ffffff');
    radgrad.addColorStop(0.75,'#333333');
    radgrad.addColorStop(1,'#000000');
    ctx.fillStyle = radgrad;
    ctx.fillRect(10,10,200,200); 
}
window.onload=function(){
    draw();
}
</script>
</head>
<body>
<canvas id="myCanvas" width="300" height="240"></canvas>
</body>
</html>
